Steadicam - rental w/o op? or, the "Occaisional Op"?

I've used my little Steadicam JR for years, but a few times I've wanted to shoot with a bigger cam, thus requiring one of the larger (waaay more expensive) Steadi rigs. Any comments on availability of rental rigs w/o operator, whether rental shops would offer any setup training, and would my fairly extensive JR experience translate to a workable experience on the larger rig? By larger rig, I mean the 8-20 lb rigs, not the Studio III (or whatever's at the top of the pack now).

I am not knowledgeable about your experiences with steadicam jr, but I can say that it is a different world as you step up the ladder toward a full
strength steadicam. There are some camera houses out there that might have larger rigs, however, I am not sure who they are.
I beleive PRO, Paddock radical options, in the LA valley rent out steadicam rigs. They may only rent out to steadicam operators whose rigs are being serviced. I don't know, but you can check them out. I know there are some steadicam sites out there for operators who can guide you into rentals and courses and so on. May your back be with you.